Cutterhead with constant length retaining cutters



W. G. OTTO Sept. 12, 1950 CUTTERHEAD WITH CONSTANT LENGTH RETAINING CUTTERS Filed June 18, 1947 V f Rm m m M V/w w. w W m Patented Sept. 12, 1950 Ap iieanenuuners, 1siijseriarnogissp'sz This invention relates t shaping cutters and more particularly to. a cutter head with constant length retaining cutters.

Heretoforeit has been possible to sharpen the dulled cutting edges; of .a rotary shaping cutter, but in doing so, even though 'they groundiorm of the cutter could bemaintained, theradius distance of the cutting edge to the center of rotation 'of t 'he shaping tool will be reduced due to the grinding away of the cutter :stock. There are,l'however,. applications where it would be most desirable and advantageous to grind the-cutting edgesbf rotary cutting tools and maintain-constant not only the form, but also the diameter.

An object of this invention is to provide a new and efficient shaper cutter whose cuttingmembers will maintain a constant form and constant position regardless of the number f times they are sharpened.

In accordance with one embodiment of this invention a rotating shaper cutter is provided with a plurality of removable cutting members secured, by wedge clamps, in V-shaped notches transversely cut in the rim of an annular frame. The ground form of each cutting member is parallel to the base of the cutting member, and the angle between the base and the forward or cutting face of the cutting member is the same as the angle between the sides of the V-notch so that if the cutting member is sharpened by the apparatus shown in Fig. 1 taken on the line 2-2 of that figure;

Fig. 3 is a cross-sectional View of a piece of material shaped by the apparatus shown in Fig. 1;

Fig, 4 is a cross-sectional View of a piece of material processed from both sides by a pair of oppositely rotating shaper cutters as shown diagrammatically in Fig. 5; and

Fig. 5 is a diagrammatic showing of a pair of oppositely rotating shaper cutters working on both sides of a piece of material.

In the accompanying drawing, a shaper cutter -1-Olaim. (Cl. 144230) it --errib'o dying features o'f ithe invention shown clamped betwe'en a pair of collars l l and l z ona rotatable-shaft P3 which' niay be palt or a wecd annular shoul'd'er 1P4 on'fthe shaft 3' and-a niit l-5 screwe'd on the threaded end "of tliesliaft 13. .The 'pai ti'ciilar aground izform 6f the "cutting members showh is 'adapted toslfape wcod o other material esto'ck to tthe icross secticn shdwn in Fig. 3. A :d'owel rod :having the cross rsectionshown in iEig, r14 smayiabershaped iby using a pair or opp-ositely zrev-dlving :shaper cutters shown dilagrammatically in Fig. 5 to work on both sides of the material stock. The amount of stock removed by the cutting members is indicated by the dot and dash lines in Figs. 3 and 4.

As will be seen in the drawing an annular cutter holder 16 provided with a central aperture I! for shaft-mounting provides support for a plurality of cutting members l8 which are disposed in V-shaped notches I9 extending transversely across the periphery of the cutter holder The oppositely disposed surfaces of the cutting I6. Each of the cutting members I8 is firmly held in place by a clamping shoe 20 which is forced against the back face 2| of the cutting member and the back part 22 of the V-shaped notch i 9 by means of a flat head machine screw 23 which passes through an elongated and counter-sunk aperture 24 formed in the clamping shoe 2!] is screwed into a threaded aperture 25 in the frame 16. A safety pin 30 attached to the clamping shoe 20 extends into an aperture 3| formed in the cutting member I8 in order to prevent the cutting member from flying out of its position in case it becomes loose while the cutter is rotating. To prevent misalignment due to dirt, etc., in the apex of the V-shaped notches, the apex of each notch may be slightly undercut as shown at 32.

Each of the notches [9 in the cutter holderis is defined by a pair of walls Hand 33, the wall 22 being disposed parallel to the ground form 34 of the cutting member I8 when the cutting member is mounted in the notch and the wall 33 beingdisposed at the hook angle or top rake angle.

of the cutting member in position in the notch.

member 18 are parallel one to another so that When thecutting member is in proper position its base 35 rests on the wall 22 of the notch I9 and its forward face 36, which is flat, is contiguous to and parallel with the wall 33 of the notch, which wall is onthe line of the desired hook angle of the cutting member l8.

To sharpen a cutting member 18 it is removed from the cutter holder I6 and its forward face 36 is either ground or honed until the cutting edge 40 of the member attains the desired degree of sharpness. It is important that the original angular relationships between the faces and ends of the cutting member be thegsame before and after thejfgrinding or honing of the forward face 36. After sharpening, the cutting member I8 is replaced and clamped in the notch IS with its forward face 36 again contiguous to and parallel with the Wall 33 of the notch" 19 and its base 35 lying flat on the surface of the wall 22 of the notch. It will be seen that aftersharpening, even though the thicknessxof the cutting member 18 has been reduced, the ground form 34 will 4 0nd face, a substantially cylindrical cutter holder rotatable about an axis passin therethrough and having a V-shaped tool receiving notch therein formed by a flat first face and a flat second face forming an obtuse dihedral angle similar to said obtuse dihedral angle of said tool and meeting at a line parallel to the axis of said cutter holder, said V-shaped notch extending inwardly from the periphery of said holder with the line formed by said two flat surfaces being disposed intermediate the axis and the periphery of said holder, and

remain constant and the relative position of thecutting edge 40 with respect to the axis of rotation will remain unchanged.

What is claimed is:

1.". A-' shaper, cutter comprising a cutting member having; a-flrst flat face and a second flat face forming a predetermined obtuse dihedral angle and a thirdfaceclisposed opposite to said second face, and adjacent said first face, said third face ofz saidp cutting tool -b eing disposed at an acute angle ;;relative to the first; face thereof and forming therewitha cutting edge, said third face sloping relative to ,said firstface in the same direction as said secondface and with any line in said third face formed by a plane perpendicular to said firstfaee and saidvsecond face and intersecting. sai'd third face, being parallel to said secmeans for clamping said cutting member in said notch with the dihedral of the tool coinciding with the dihedral of the holder and with the first face of the member engaging with the first face of the notch of the holder, said first face of said notch forming a predetermined hook angle with a plane drawn from the cutting edge of said member in assembled operative position in said cutter holder through said axis.

WILLARD G. OTTO.

REFERENCES CITED The following references are of record in the,

file of this patent:

UNITED STATES PATENTS Number Name Date 237,652 Woods Feb. 8, 1881 707,035 Tindel Aug. 12, 1902 999,014 De Laney July 25, 1911 1,451,995 Madsen Apr. 1'7, 1923 

